# Package titlesec adds spacing around \section even with \titlespacing all set to zero

My minimal example looks like this:

\documentclass[12pt]{article}

\usepackage{color}
\usepackage{framed}

%\usepackage[compact]{titlesec}
%\titlespacing{\section}{0mm}{0mm}{0mm}

\begin{document}
\section*{Abstract}
\end{document}


which results in

However, if I uncomment the lines to add the titlesec package, the result looks like this

Obviously, \titlespacing{\section}{0mm}{0mm}{0mm} is not enough (or even wrong?) to return to the previous spacing. What are the right commands to make titlesec do this?

titlesec doesn't add spacing. But it adds a strut so that every section has the same height and depth. Compare this here (without titlesec) with a second section with small content:
and this output from titlesec:
• Oh, okay. Thank you. So, it's a feature then? I guess there is no way to disable this in titlesec other than patching its commands? – finefoot Dec 20 '17 at 23:21
• Alright, thanks :-) Even if you're not the author of titlesec, you still seem to have a lot of experience with it. Certainly more than I have. So why shouldn't you know something about the "why" I asked? A reason a beginner like me maybe doesn't think of. That's why I asked. :-) – finefoot Dec 21 '17 at 13:56